Dust collector for grinding operations



y 7, 1946 I E. F. FISHER v zwww I DUST COLLECTOR FORTGRINDING OPERATIONS Filed Aug. 17, 1943 5 Sheets-Sheet l 1 we 11 KM m/wssr fins/mi 7 ii-:1 E. F. FflSHER DUST COLLECTOR FOR GRINDING OPERATIONS Filed Aug. 17, 1943 5 Sheets-Sheet 2 May 7, 1946.

E. F. FISHER DUST COLLECTOR FOR GRINDING OPERATIONS Filed Aug. 17, 1943 5 Sheets-Sheet 3 W E H W ,5 7

. y 1946- 1 E. F. FISHER 2,399,629 DUST COLLECTOR FOR GRINDING OPERATIONS Filed Aug. 17, 1943, 5 Sheets- Sheet 4 M T W- May 7, 1946. n-:. F. FISHER DUST COLLECTOR FOR GRINDING OPERATIONS Filed Aug. 17, 1943 5 Sheets-Sheet 5 mentioned aspirating nozzle.

reamed May 7, i946 DUST COLLECTOR FOR OPERATIONS GRINDING Ernest F. Fisher, Harvey. IlL, assignor to Whiting Corporation, nois Harvey, 11]., a corporation of Illi- Application August 17, 1943, Serial No. 498,960

(Cl. 5l-2i3) 8 Claims.

The present invention involves a new and improved booth for collecting and precipitating dust from grinding and polishing operations, particularly such dangerous dust as from the grinding of aluminum and magnesium castings.

According to this invention, a fluid aspirating nozzle projects a stream of liquid, or a mixture of liquid and'air into a Venturi tube. This fluid spray, in cooperation with the Venturi tube creates a strong suction in a conduit which is connected with a dust hood or the like where the dust is being created, the suction operating to draw the dust from the .hood into the conduit where it is thoroughly wetted by the water from the spray nozzle and is then projected into the Venturi tube where it is further wetted, and

thence into an enclosure into the bottom of which.

it drops as sludge. The sludge chamber is provided with a partition for effecting a separation between the settled sludge and clear water, the

clear water being recirculated through the above In the preferred arrangement, compressed air is supplied to the aspirating nozzle, creating a suction which draws up clear water from the clear water chamber, thereby making it unnecessary to use a mechanical pump.

The invention will be further described in connection with the accompanying drawings in which:

Fig. 1 is a vertical section of the dust collecting booth of the present invention, taken on line l-l of Fig. 6.

Fig. 2 is an end elevation of Fig. 3, on an enlarged scale, showing the aspirating nozzle.

Fig. 3 is a section taken on line 33 of Fig. 2.

Figs. 4 and 5 are sectional views taken on the lines l- -"i and 5-5 of Fig. 3, respectively.

Fig. 6 is a vertical elevation, partly in section, on the line 6-43 of Fig. 1.

Fig. 7 is a section on the line 1-? of Fig. 1.

Fig. 8 is a vertical sectional view of a modification, taken on line 8-8 of-Fig. 9.

Fig. 9 is an elevation view of the modification looking toward the right of Fig. 8.

Fig. 10 is a section on the line ill-l of Fig. 8.

Referring now to these drawings, the apparatus of Figs. 1 to '7, inclusive comprises an enclosure it including a front wall 4 and a rear wall 6, the bottom of the enclosure containing a sludge chamber 8 and a clean out hopper l0. Conventionalfloat means l2, illustrated only diagrammatically, maintains theliquid level constant at about the level shown in Fig. 1.-

Positioned on the wall 4 is a housing l2 for an aspirating nozzle, the latter being indicated generally at N. This aspirating nozzle comprises an inner tube 16, Fig. 3, for compressed air, this tube l6 communicating with a vertical passage 20 in a stream-lined housing member 22. Compressed air is supplied to the passage 20 from a pipe 2 3. v

The tube 06 is mounted centrally in a larger bore 26 in the housing 22 and in this larger bore is a nozzle 28 which is mounted concentrically with, and surrounds, the tube IS. The bore 26 communicates with a passage 30 in the housing 22, and a water pipe 32 delivers water to the passage so from a clear water compartment 34' in the bottom of the enclosure 2.

It will be -apparent from the foregoing description that when compressed air is supplied to the tube l5, suction will be created in the bore 26. such suction tending to' draw up water through the pipe 32 so that there is projected from the nozzle M a spray in the form of atomized water and air under pressure.

This spray of water and air is projected into a Venturi tube '38 which is positioned horizontally on the wall. t of the enclosure 2. As shown in Fig. '7, one end of the Venturi tube is provided with downwardly projecting walls 38 which dip below the level of the water in the sludge chamber ii to make a water seal, effectually preventing entrance of air, so that water and sludge can readily drain into the sludge chamber 8 from this end of the venturi as well as from the other end. The dust, as it passes through the Venturi tube, is brought into intimate contact with the spray and thoroughly wetted, so that there is no possibility of explosion, if the dust is of the explosive or inflammable type.

The nozzle housing i2 is connected with a conduit M which in turn is connected to a hood 42 that nearly completely' surrounds a grinding wheel M.

The aspirating nozzle i l createsin the conduit it a suction which is transmitted to the hood M so that dust from the grinding wheel under the influence of this suction and aided by the initial tangential velocity imparted to it by the grinding wheel, passes into the conduit into contact with the spray from the nozzle M and is projected into the Venturi tube and thence into the enclosure 2, thereby thoroughly wetting the dust which drops into the sludge chamber 8.

A curved guard 56 is positioned above the discharge end of the Venturi tube for preventing the upward passage of dust. The water spray serves to wet any particles of dust that collect on the sludge chamber. Spray interceptor plates 38 are provided in the upper discharge part of the enclosure 2, through which the clean air is discharged.

The heavy wet sludge is guided by a diagonal partition 56 toward the clean out hopper it from whence it may be removed from time to time. The partition 56 is provided with a number of strainer holes 52 in its upper portion so that the clear water in the upper part of the sludge chamber will pass through into the clear water chamber ti l for recirculation through the nozzle Ml. The float valve i2 supplies additional water through a pipe not shown, as needed to keep the water level substantially constant. A sediment drain or washout connection for chamber M is provided at 53.

In operation, the aspiratlng nozzle, operated by compressed air, projects aspray of Water and air into the Venturi tube, the combined action of the nozzle and Venturi tube creating a strong suction in the conduit to and in the hood lli, drawing the dust and air into the water spray,

projecting the mixture through the venturi, and

thoroughly wetting the dust and precipitating it as sludge into the sludge chamber 8.

Referring to the modification shown in Fig. 8, the Venturi tube 54 is mounted so that its throat is in about the same plane as the wall 4, the inlet end of the Venturi tube being directly secured to the hood 42 of the grinding wheel 44, making a somewhat more compact construction than in Fig. l. The enclosure for the inlet end of the venturi is completed by the diagonal wall 56 and also the vertical wall 58 which is connected to the hood wall 42. A water pipe 60 delivers water under pressure to a spray-nozzle 62 mounted on wall 58 to project a water spray into the Venturi tube.

The wall 56 is extended into the lower part or thev enclosure 2' to define a sludge chamber 62 and a clear water chamber 64, strainer holes 66 being provided in said wall to allow the clear water from the upper part or the sludge chamber 62 to drain into the clear water chamber 64. The sludge that collects in the chamber gravitates toward the lower end thereof, where it is removed through a conventional clean out hopper 'of the type shown in Fig. 1 or through a drain 61. A drain 69 is used for draining sediment from the chamber 64.

A pump 66 draws water from the clear water chamber 64 and delivers it to the pipe 60 for projection through the spray nozzle 62. The discharge end of the Venturi tube is preferably square as shown in Fig. 10.

A wall or partition 88, which is a projection of wall 4, extends below the surface of the water in the sludge chamber and, in efiectdorms a water seal which prevents by-passing of the air around the Venturi tube 54, and has the same function as wall 38 of Fig. 1.

In operation, a powerful spray of water from the nozzle 62 creates suction in the hood 42, thus drawing the dust entrained with air into contact with the spray, the suction effect being further enhanced by the use of the Venturi tube 54. The dust is thoroughly wetted as it passes through the Venturi tube and falls into the sludge chamber 62, any dust that might have escaped being caught by the guard plate 48. The clean air passes out through eliminator plates '10 as in Fig. 1.

While the invention has been described in some lined housing and positioned in said conduit, said nozzle housing being provided with a passage for compressed air and with a water passage con nected to said chamber, said nozzle being for simultaneously projecting air and water into the Venturi tube, for creating suction in the conduit and for projecting wetted dust against the opposite wall of said enclosure, and a dust collector connected to the suction end of said conduit.

2. A dust collector for grinding operations, comprising an enclosure, a Venturi tube opening intosaid enclosure, a dust collecting hood connected to the inlet end of the Venturi tube, liquid spray means including means for supplying compressed air thereto as the propelllng agent for the liquid, for projecting liquid into the inlet end of the Venturi tube, said spray serving to wet dust passing through the Venturi tube and also serving as the sole means for creating suction at the inlet end of the Venturi tube.

3. A dust collector for I grinding operations, comprising an enclosure having a chamber in the lower part thereof divided into sludge and clean water compartments, a Venturi tube opening into said enclosure chamber, a dust collecting hood connected to the inlet end of the Venturi tube, water spray means, including means for supplyingv compressed air thereto as the propelling agent for the water, connected to said clean water compartment for drawing 1 clean water therefrom and projecting it'into theinlet endv of the Venturi tube, said spray serving to wet dust passing through the Venturi tube and also serving as the sole means for creating suction at the inlet end of said Venturi tube.

4. A dust collector -for grinding operation comprising an enclosure including a solid surface, a horizontally disposed 'Venturi tub'e opening into said enclosure, dust collecting means connected to the inlet end of the Venturi tube, spray means for projecting a horizontal spray oi! liquid into the inlet end of the Venturi tube, said spray means including means for supplying compressed air thereto as the propelling agent for the liquid, said spray serving tocreate a suction for drawing dust-into the inlet-end of the Venturi tube from said dust collecting means, and to wet the thereof divided into sludge and clean water compartments, a horizontally disposed Venturi tube opening into said enclosure above the chamber, dust collecting means connected to the inlet end of the Venturi tube, and spray means, actuated by compressed air and connected to the clean water compartment for drawing water therefrom and projecting it into the Venturi tube, said spray serving to create a suction for drawing dust into the inlet end or the venturi from said dust collecting means and to wet the dust and to project the wetted dust against said solid surface and 6. An apparatus for suppressing dust from a grinder wheel or the like and comprising an upstanding enclosure type casing having a sludge receiving sump in the bottom thereof and an air outlet at the top, a substantially horizontal Venturi tube opening into the casing above the sump, a conduit leading from the grinder wheel to the receiving. end of the Venturi tube, and means adjacent said receiving end of the Venturi tube operative to spray liquid under pressure horizontally through the Venturi tube into the easing and thereby cause air to flow through the conduit and tube and thence from the casing via said outlet.

7. An apparatus for suppressing dust from a grinder wheel or the like and comprising an upstanding enclosure type casing having a sludge receiving sump in the bottom thereof and an air outlet at the top, a substantially horizontal Venturi tube opening into the casing above the sump, a conduit leading from the 'grinderwheel to the receiving end of the Venturi tube, means adjacent said receiving end of the Venturi tube operative to spray liquid under pressure horizontally through the Venturi tube into the casing and thereby cause air to flow through the conduit and tube and thence from the casing via said outlet, and an angularly arranged deflector in the casing disposed adjacent the discharge end of the Venturi tube and serving to deflect upwards towards the outlet the air that passes through the Venturi tube and also to deflect downwards into the sump the sprayed liquid after the latter passes through said Venturi tube. 7 I

8. An apparatus adapted to suppress dust from a grinder wheel or the like and comprising an upstanding enclosure type casing having a sump Y onally extending wall disposed in the sump, servduit and tube and thence out of the casing via the outlet, and embodying a nozzle adjacent said receiving end of theIVenturl tube and a conduit between the clear water compartment and the nozzle.

- ERNEST F. FISHER. 

